1. Field of the Invention
The present invention is directed to manually operated window shade assemblies adapted in particular for use in windows of airplanes, that are readily assembled and installed, and which provide convenient and reliable operation. More particularly, the present invention is directed to a manual override mechanism for a motorized window shade actuator wherein manipulation of the override mechanism causes release of a motor and allows manual movement of a window shade to an open position.
2. Description of the Related Art
The motorized window shade assembly disclosed in U.S. Pat. No. 6,186,211 was a major improvement over other mechanisms known at that time and is highly effective in reducing the number of components required, increasing reliability, and meeting the rigid requirements associated with the use aboard aircraft. The shade assembly disclosed in the aforementioned patent includes a pane behind which the shade material, i.e. the shade fabric, is mounted such that direct user contact with the shade material is prevented. As such, the window shade assembly utilizes actuators controlled by electric motors which receive operating power from an aircraft power bus, as is known in the art, to raise and lower the shade fabric. Further improvements of window shade mechanisms are disclosed in U.S. Patent Application Publication No. 2011-0108208 (Ser. No. 12/943,569) filed on Nov. 10, 2010, the content of which is incorporated by reference.
It is desired and in many instances required that the shade fabric of motorized airplane window shades of the type disclosed in U.S. Pat. No. 6,186,211 be moveable to its open position in certain circumstances, such as during plane landing, or in the event of an emergency. During plane landing, when operating power continues to be supplied to shade actuators, such as motors, shades can be raised in their normal operating manner by selecting the “up” or “open” button. During an emergency condition, however, shade operating power may cease, thereby rendering motorized shades—where access to the shade fabric does not exist—inoperable. In such an emergency condition, the shade fabric will be unable to be moved to its open position
Accordingly, a need exists for a passenger-accessible manual actuator which allows a passenger to raise a shade fabric of a motorized shade assembly to an open position in the event of loss of operating power to the shade assembly.